Problem: Excessive Heat - Hose cover and/or inner tube is brittle, cracked, not flexible at room temperature.
Solution: Use a hose with a higher temperature rating, or protect the hose from external sources of heat with shields.
Excessive working temperatures, where the medium flowing through the hose is hotter than the hose's rating, will cook the inner liner and quickly ruin a hose.
High ambient temperatures also shorten hose life. Route hoses away from heat sources or insulate the hose from excessive heat using a fire sleeve.
Very low ambient temperatures can also shorten hose life, causing a hose to crack. It is important to check the temperature rating of the hose listed in the manufacturer's catalog
Source: Gwyn O'Kane, Director of Training, Pirtek USA.